A day on the flow bench

[David Buschur]

Today I spent the majority of the day on the flow bench. The findings were quite interesting.

The numbers below are the cylinder and CFM. All testing was done at 28" on a JKM Flow bench by BRS head services.

Here are the results of what I have found so far.

EVO8 Stock intake, w/stock throttle body:
#4-327, #3-308 (-6%), #2-300 (-9%), #1-300 (-9%), total 1235 CFM

BR Ported intake, w/65mm throttle body:
#4-336, #3-319 (-5%), #2-306 (-9%), #1-300 (-12%), total 1261 CFM

BR ported intake, w/65mm throttle body, additional port work
#4-337, #3-318 (-5%), #2-310 (-8%), #1-300 (-12%), total 1265 CFM

BR ported intake, w/65mm throttle body, even more port work
#4-331, #3-319 (-3%), #2-315 (-5%), #1-300 (-10%), total 1264 CFM

Wilson V2 intake, w/65mm throttle body
#4-330 (-3%), #3-329 (-3%), #2-321 (-5%), #1-340, total 1320 CFM

Driven Innovations, w/65mm throttle body
#4-320 (-5%), #3-324 (-4%), #2-334 (-1%), #1-337, total 1315 CFM

Stock intake manifold with no port work done to it. The plenum cut off basically flush to the top of the runners. We put that on the flow bench and checked it.

#1-308cfm(-12%), #2-320cfm(-7%), #3-341cfm(-1%), #4-345cfm

This was quite shocking as the #1 runner hardly gained anything at all. The plenum/runners didn't seem to be the biggest problem in the intake at this point.

We then did some additional port work on just #1 and it changed nothing, still flowed 308 cfm.

Then we started playing with clay in the port to try to pick it up, again, no major changes. There was one last shot at making it flow better with something we are capable of doing here at the shop so I had Trent weld up part of the #1 port and did some grinding on it.

That port then went up to 316cfm with no plenum on the intake manifold.

I came back to the shop and grabbed the stock BR ported intake we were working with yesterday and duplicated what we did on the cut apart intake, the best I could. It's very hard to reach that runner in the intake as it's all the way in the back of the plenum.

The next flow test was very good and is as good as we can get it without trying to cut apart an intake manifold and copy someone's else's work, which I have no desire to do.

So here's how we ended up on the final port work on the stock intake:

#1-314cfm(-5%), #2-308 cfm(-7%), #3-315cfm(-4%), #4-330cfm
Total CFM 1267.

Back on the flow bench. The Wilson V2 OFF MY RS and the ported stocker we have been working on:


Wilson V2 off my car:
#1, 340cfm
#2, 322cfm (-5%)
#3, 330cfm (-3%)
#4, 325cfm (-4%)
Total CFM, 1317

The BR extra ported intake we have been working on:
#1, 317cfm (-3%)
#2, 313cfm (-4%)
#3, 313cfm (-4%)
#4, 327cfm
Total CFM, 1279

Now some interesting notes on this. The total CFM shows that the results from the flow bench also directly match up to what I have seen thus far on the dyno testing. That is very interesting. Also, it is interesting to look at the balance from runner-to-runner on the intakes. We have been able to balance our standard ported intake out through some additional work.

When this flow bench testing is finished I will be running more tests on my RS on the dyno.
__________________

[vwjeff]

Its amazing how screwed up all those #'s are on the runners... thats bad no? Dont we want them equal? Total CFM is good for me though

Thanks for doing all this mang!!!

[steelcityevo]

David I hate to ask stupid question but ,

Is the numbers from left to right as you would look at the manifold on the engine from the front of the car?

Just trying to clarify exactly which runner is which?

Maybe you should have kept my manifold up there to throw on there with the Extrude Honing and the portwork that Ted did to it !!!!!

[Spoolin0nYou]

You've gotta throw a head on the flow bench to see how much each of the individual intake ports flows...while they should flow the same, I'm betting they're not...and I'm betting they don't flow as much as the manifold.

Why have an manifold that outflows the intake ports? That doesn't make much sense to me.

[David Buschur]

The numbers are in reference to the cylinder.

#4 cylinder for reference on the EVO is the port right next to the throttle body opening. #1 is of course the very end opposite the throttle body.

The cylinder head on the bench, by itself, with no header/no intake manifold does not flow as much as the intake ports do.

Why have an intake that flows more than the cylinder head? That is an interesting question but as can be seen by these numbers that if the intake flows more then the car makes more power. Obviously it has an effect, even if it doesn't make much sense now that you mention it.

The stock intake, unported with the stock throttle body, for reference outflows the EVO head too.

As for the head flow on the bench, the head flow from cylinder to cylinder on the EVO heads we do are extremely close actually.

[steelcityevo]

David

If your interested in the Extrude Honed plus ported manifold for testing just let me know.

It sucks It must be in transit right now. But shit I would ship it right back if you wanted to piss around with it haha.

Dan

[steelcityevo]

Its also interesting to see that the Wilson and the DI manifold basically flipped the results completely opposite as far as which end of the manifold flows better compare to stock.

stock flows best from port 4 to port 1

the Wilson and DI flow best from port 1 decreasing to port 4

What do you think that is from Dave?

Dan

[David Buschur]

Well..............we are getting quite a good grasp on what it's from actually.

The DI has all the runners the same length and it is the most balanced, so that's a clue. The runner is also below the inlet so the air flows smoothly to the far end of he plenum.

The stock intake manifold by comparison has different length and shaped runners and the dividers for each cylinder are very high in the plenum and it seems as though as the air is drawn or blown across the air is disturbed by those raised dividers and the further it goes across the more the flow is disturbed.

The Wilson has the dividers cut down in it so the are low which also increases the plenum size. Dropping the dividers lower is proving to even out the flow across the intake manifold.

I believe the last change we made to the intake will bring the flow up on the #1 runner substantially.

The Wilson intake is cut open in the back, ported all the way through, the runners are shortened, which enlarges the plenum, then it is welded back together and ground again. It's a lot of work. It's a beautiful piece of work, it's also $1550 and is no longer available to us to sell. Poor choice on their part and I'm not kissing someone's ass to change their mind. So it is what it is.

Our goal right now is to get the stock intake manifold that we offer ported for $140 to balance out better. I am not cutting it apart, I am not welding it and bottom line is it's not going to flow as well as the Wilson but if we can get the runners balanced the intake is going to work a heck of a lot better. It is more time consuming and will add some cost. I'm going to dyno them all when I am done with this and see what works best.

This stuff isn't rocket science, I can tell you that right now. I wish I had thought about flow benching each runner when we started porting these years ago. It never even occured to me at the time to see how balanced each runner was. Now it looks for sure to have an effect on the power.

I also want the 57 whp I lost back at 4500 rpm. I'm hoping for the best average WHP across the RPM band by the time we are finished.

[yellowevo42]

Flow numbers on the DI intake has me boggled. I thought that was supposed to be a premeir intake manifold for the evo?

[farook]

Numbers for the DI look pretty damn good to me, flows a high volume with little turbulence/change in total flow between the runners. Wasn't to far off of the port work of one of the premier intake guys in racing.

[yellowevo42]

Well ya i guess i skimmed over it a bit but #4 and #3 are lower then others

[Spoolin0nYou]

The numbers are in reference to the cylinder.

#4 cylinder for reference on the EVO is the port right next to the throttle body opening. #1 is of course the very end opposite the throttle body.

The cylinder head on the bench, by itself, with no header/no intake manifold does not flow as much as the intake ports do.

Why have an intake that flows more than the cylinder head? That is an interesting question but as can be seen by these numbers that if the intake flows more then the car makes more power. Obviously it has an effect, even if it doesn't make much sense now that you mention it.

The stock intake, unported with the stock throttle body, for reference outflows the EVO head too.

As for the head flow on the bench, the head flow from cylinder to cylinder on the EVO heads we do are extremely close actually.

I believe it works the same way as IC pipes/cores. The least restriction before the bottleneck into the combustion chamber, the better. If it flows too much, the efficiency range is lowered, and the turbo has to work harder. At least, that's my theory.

The key in any great setup is finding the perfect balance between parts. The HTA35r and the FS635 are both great turbos. Matching them with equally ported manifolds to match their efficiency range is the key in making the most usable horsepower.

Rumor has it that you're hiring...so, when do I start my first day @ Buschur Racing?

[manley57]

From what I've seen the big flaw is the design of the runners and tube off the TB my design would be a total departure from the current ones, this would force more air to the intake ports #1 and 2 that are the farthest away from the throttle body.
If BR would like I can draw it up and let you take a look see.

[David Buschur]

The DI has the most balanced runners of the intake manifolds and very close to the best flow. I'd say that's a pretty good outcome.

Today is going to be a GREAT day. We have two more things we are going to try. First we want to get #4 runner on our ported stock intake up closer to the rest, that will be the first flow bench test.

Then the second is on a bone stock intake manifold with the plenum completely cut off. This is to figure out if the plenum is what's effecting the imbalance of the runners or if it's the runner length/shape. Once we have that figured out................LOOK OUT!!! haha Some things are going to change up in here!!

[SloRice]

I'd be interested to see this one flow benched. I have some thoughts on it based on the outcome.

[David Buschur]

Here are some pictures of the flow bench work.

[boost3dxevo]

Looking forward to updates!! Nice project!

[David Buschur]

I put the intake back on the bench after more port work and there was no change in #1 runner. Very disapointing indeed.

Also, I put the i/c pipe on the throttle body at the angle it is installed on the car. The CFM's dropped about 5 CFM, so it lost some flow. I then turned it as far in one direction as I could and then rotated it back the other direction as far as I could. So over 180 degrees in rotation. By doing this the most it would effect any runner was less than 2 CFM of loss or gain. Very small change, seems like the biggest restriction is the pipe alone and that moving it around has little/no effect on air flow from there. Our pipe does have a 90 degree bend in it but remember after the bend it has about 2" straight and the length of the throttle body/intake manifold flange is another 3.5", I believe that length of straight is getting the air flow stabilized again and moving straight into the throttle body.

We then put the intake manifold on the flow bench minus the plenum. The results are still messing with my head. I will post more on that when I am done.

[OLDSCHOOLMOTORS]

Flow bench should be named " The Heart Breaker " too .

Glad to see your testing to see what really works , shame the money that has been spent on EVO/DSM intake manifolds in the past only to get sub-par designed parts at high prices.

Seems the only R&D put into them was making the jig , people were wowed by the shine and fancy welding and expected the manifold to preform as good as it looked.


Now when are you going to get started on testing exhaust manifolds ? I'd like to see some results on the high priced , long wait , purty manifolds , we all have come to love , compared to cast and other competitors.

[David Buschur]

Wow. Learned a lot today.

Here are some additional numbers to throw around.

Stock intake manifold with no port work done to it. The plenum cut off basically flush to the top of the runners. We put that on the flow bench and checked it.

#1-308cfm(-12%), #2-320cfm(-7%), #3-341cfm(-1%), #4-345cfm

This was quite shocking as the #1 runner hardly gained anything at all. The plenum/runners didn't seem to be the biggest problem in the intake at this point.

We then did some additional port work on just #1 and it changed nothing, still flowed 308 cfm.

Then we started playing with clay in the port to try to pick it up, again, no major changes. There was one last shot at making it flow better with something we are capable of doing here at the shop so I had Trent weld up part of the #1 port and did some grinding on it.

That port then went up to 316cfm with no plenum on the intake manifold.

I came back to the shop and grabbed the stock BR ported intake we were working with yesterday and duplicated what we did on the cut apart intake, the best I could. It's very hard to reach that runner in the intake as it's all the way in the back of the plenum.

The next flow test was very good and is as good as we can get it without trying to cut apart an intake manifold and copy someone's else's work, which I have no desire to do.

So here's how we ended up on the final port work on the stock intake:

#1-314cfm(-5%), #2-308 cfm(-7%), #3-315cfm(-4%), #4-330cfm
Total CFM 1267.

I'm going to paste this information into the first post too so it's easier to compare.

I will be taking the Wilson intake off my car that's on there now in the next few days (I sold it). I will run the car first with the Wilson and then with this one. I'm hoping to gain back some of the low/mid range power I lost and figure I will be coming up short on power up top. That's fine. There's more to come. I may test some other aftermarket intakes this same way.